1. Field of the Invention
The present invention relates to an optical fiber cable lead-in structure.
2. Description of the Related Art
In communication equipment such as optical communication equipment, an electronic circuit unit (hereinafter referred to as "unit") mounted on a shelf is usually connected electrically and optically to other units and an external apparatus through a back wiring board situated at the back surface of the shelf. However, these units are now highly densified and connection of the units to the back surface of the shelf only is no longer adequate and it is imperative to use the front space of the shelf as well.
Referring to FIG. 6, which discloses an example of such a shelf, the front surface of the shelf 61 is almost covered by the surface plates 63 of many units 62 that are mounted in parallel formation inside the shelf. An optical fiber cable 67 has at its end an optical connecter 69 that is detachably connected to a corresponding optical adapter 65 of each surface plate 63. Each of the optical fiber cables 67 is attached perpendicularly to the surface plate 63 and the cable portion thereof is extended to describe a large arch for connection to other units and the external apparatus and is led and received in a remaining cable receiving space 71 provided between the upper and lower surface plates 63.
In the above optical fiber cable lead-in structure, a problem has been that the cable portion is forced out of the front side of the shelf and it is difficult to protect the optical fiber cable 67, which is subject to damage by bending. It has also been found that a large space is needed to install such a shelf (equipment) 61 with outwardly extending fiber cables.